OBJECTIVES: Private claims databases have been a rich source of information related to healthcare delivery, though the fragmented nature of U.S. health insurance market limits their ability to provide a comprehensive view of a given geography. Additionally, claims data are often expensive (>$25,000) - restricting access to those with the economic means to afford it..  To provide a more thorough view of health costs and practice at the state level, 11 states have created all payer claims databases (APCDs).  An analysis was conducted to review their designs and consider how they will impact health economic analyses and health services research. METHODS: A detailed review of 11 APCDs was conducted using a combination of secondary research and key informant interviews.  This included reviewing the legislation that mandated and funded their creation, the rules under which they operate, and the data they collect and make available.   The multi-state analysis was then informed by a deeper analysis of the data integration opportunities, reporting abilities, and costs for data exchange for Maine’s newly revised APCD. RESULTS: Across states, APCDs make publicly available a wide array of health data in a manner that ensures privacy and security of personal health information. Each APCD provides varying levels of granularity in health care resource utilization, demographic comparisons, expenditures, and quality/safety data. Ability to customize data pulls is growing, though private claims datasets appear to have greater flexibility.  In Maine’s APCD, commercial and Medicaid medical, pharmacy, and dental data are available to researchers, with quarterly block releases and opportunities for individual queries. CONCLUSIONS: APCDs are providing researchers with an open-access, affordable pathway to understand health care resource utilization and practice across entire populations.  As more come online, greater participation in health economic and health services research can be expected.